Chest freezers are perfect for these builds as their top door design helps keep the cold air inside to boost the efficiency. The trick is to modify them without messing up the insulating properties of the appliance housing. [GMMN’s] approach is a common one, build a cuff to go in between the lid and the body of the freezer. He started by building a wooden box open at both the top and the bottom. Many would have stopped there but to bring the bling he tiled the sides and front of that cuff, leaving an empty spot for the shank of each tap. With that taken care of he glued insulation to the inside of the cuff, and added weather-stripping to the bottom to seal with the top of the case. He used the holes from the lid hinge brackets to attach his add-on so that the freeze can be converted back to stock without any sign of his alterations.

15 thoughts on “Building a kegerator with visual style”

Maybe Ishould clean my glasses, but I first read: “keygenerator”, then saw the picture and thought: “wow, using entropy from some – what is this – water faucets or something. Whoever made this is a genious.”

But, no, turns out its just someone who likes his beer cold. Booooring!

Cool build and fairly simple concept. If I was to go a step further I wold replace the labels with 16×2 Matrix displays showing the brand of beer and like the post said, the second line would be a bargraph (0-100%) showing how full the keg is.

How would you gauge fullness? Positive-displacement impeller, like a water meter? Weight with strain gauges from which the kegs were hung? I wonder…anybody have any ideas? You can only judge by temperature if you’re using a hand to warm it up.

One idea I’ve mulled around for a while is suspending a few wires at various lengths into the keg and measuring the resistance between the keg wall/lowest wire and the others. You should have continuity with any wires the liquid is tall enough to immerse the tip of. They could be configured for 25, 50, 75% full etc. Problem is I can get the same ballpark idea by just lifting up the 5 gal keg so never made any headway on it. You also would have to compromise the structural integrity of the keg.

I’ve found conductive probes to have problems with even tiny amounts of corrosion affecting the resistance reading.

Perhaps try capacitive sensing. If the keg is metal just run an insulated wire down inside the keg, Alternatively place that wire inside a thin conductive pipe, to form a sensor unit- should be more linear too) In effect there’s 2 capacitors in parallel. cap 1 is a capacitor that only has beer as it’s dielectric. cap 2 only has air/CO2 as it’s dielectric. guessing beer’s relative static permittivity properties will be somewhat like water say 80, and air/CO2 more or less that of vaccum ie 1.

one problem with these very wide range variable capacitors is they seem to be able to zap 555 timers! If charged and the capacitance drops, the voltage on the cap increases to try to keep the energy of the cap constant. ie E=CV^2 so ie V2= sqrt (V1^2 * C1/C2)
PUT type relaxation oscillators reset when the voltage exceeds a threshold. so perfect when overvoltage spikes are possible. use a frequency counter(say a arduino with suitable software) to convert to level. If cap is charged with a constant current device, frequency is linear to capacitance, that is also linear to level+ofset.

Alternatively if you knew/could rely the speed of sound in beer, you could probably measure the level using a piezo speaker attached to the bottom of the keg, and send a pulse of sound up inside the keg, and time how long it took for the ping to return after it was send/bounced of the beer’s surface level. piezo speakers will work as mics too.

Ballparking the number(s) here but that would be 5ish feet to the top of the opening (average countertop + average chest freezer + cuff = 5ish feet). That means to put a new keg in there you need to get the bottom of the keg 5ish feet in the air then lower it down into the freezer. I guess what I’m saying is there is likely a chain-fall attached to the ceiling and not pictured.

Sometimes guys building a keezer will let the collar (cuff) hinge up with the lid to limit the entry height. Doing so requires leaving more space behind the freezer or putting it on wheels. And oh look, in the picture it is on a rolling platform.

For measuring the “beer remaining”, I liked stevebb’s suggestion of using a piezo as a kind of sonar. If that proves difficult to generalise for all kinds of drink, how about using a solenoid to tap on the side of the keg and measuring the duration or frequency of the “clang” for want of a better word. I suspect a full keg will reverberate for longer than a half empty one and probably at a different frequency.

Use a simple FFT (an oxymoron, I know) to detect the predominant frequency in the echoes. Probably wouldn’t work well during a noisy party though :)